Portable telephone system

ABSTRACT

A switching system ( 3 ) has, in addition to an ordinary accounting function, an origination-only accounting control unit  6  to monitor the number of message units used by an origination-only portable telephone ( 1 B) identified by a terminal identification number and to deny the origination of a call by the origination-only portable telephone ( 1 B) upon the increase of the number of used message units to a predetermined number. The origination-only accounting control unit ( 6 ) accepts the origination of a call made by the origination-only portable telephone ( 1 B) when a prescribed input about the origination-only portable telephone ( 1 B) is given thereto by a system operator by operating a predetermined terminal device ( 7 ) or the like after the denial of origination of a call by the origination-only portable telephone ( 1 B).

This application is the national phase under 35 U.S.C. §371 of prior PCTInternational Application No. PCT/JP97/02086 which has an Internationalfiling date of Jun. 17, 1997 which designated the United States ofAmerica.

TECHNICAL FIELD

The present invention relates to a portable telephone system and, moreparticularly, to what is called a prepaid type portable telephone systemwhich allows a portable telephone to make a predetermined number ofmessage units, or message units and timed receptions.

BACKGROUND ART

A prior art prepaid type portable telephone system proposed in JP-A No.3-45031 is capable of metering message units used by a portabletelephone and of stalling the portable telephone upon the detection ofcompletion of a predetermined number of message units corresponding to apredetermined value to enable the omission of both a locationregistering operation and an accounting operation to be carried out by aswitching system. The function of making message units correspond to apredetermined amount of money of the portable telephone is restored whenthe predetermined amount of money is paid.

The portable telephone for the prior art portable telephone system needsa circuitry for counting the number of message units, calculation anddata storage to carry out an accounting procedure, and hence thecomplexity of the portable telephone is enhanced accordingly, whichimpedes the miniaturization and the reduction of weight of the portabletelephone.

The accounting circuit of the portable telephone capable of carrying outan accounting procedure may be altered dishonestly, and it is difficultto prevent the dishonest use of the portable telephone.

The foregoing prepaid charging system cannot be applied to a simpleportable telephone system. A portable telephone for a current portabletelephone system is too expensive to use for the simple portabletelephone system having a prepaid type charging system.

The present invention has been made to solve the foregoing problems andit is therefore an object of the present invention to provide ahigh-security portable telephone system allowing the use of a small,lightweight prepaid type portable telephone, and to provide a small,lightweight portable telephone for the portable telephone system.

DISCLOSURE OF THE INVENTION

In a portable telephone system according to an invention stated in claim1, an accounting means is included in a switching system. A switchingsystem included in the portable telephone system counts the number ofmessage units used by each of a plurality of portable telephonesincluding origination-only portable telephones, each of which areidentified by terminal identifying information assigned thereto. Theoriginating operation of the origination-only portable telephone isdenied when the number of message units used by the origination-onlyportable telephone identified by the terminal identifying informationreaches a predetermined number of message units. Nevertheless, theoriginating operation of the origination-only portable telephone whichis identified by the terminal identifying information, is accepted whena predetermined input operation is executed.

Thus, the origination-only portable telephone can be formed in a small,lightweight construction, and the security of the portable telephonesystem can remarkably be improved.

In a portable telephone system according to an invention stated in claim2, the power key of a power switch included in the origination-onlyportable telephone is operated to close the power switch every time theorigination-only portable telephone is used for originating a call.

Thus, the power consumption of the origination-only portable telephoneis low as compared with that of an originating-and-receiving portabletelephone which is kept in a wait state, and the origination-onlyportable telephone for the portable telephone system can be formed in asmall, lightweight construction.

In a portable telephone system according to an invention stated in claim3, the origination-only portable telephone has a control panel andnumeric keys for entering telephone number information for a call arearranged on the control panel, and the origination-only portabletelephone can be connected to a power supply by operating the numerickeys.

Thus, the origination-only portable telephone need not be provided witha power key, so that the size and the weight of the origination-onlyportable telephone can be reduced accordingly.

In a portable telephone system according to an invention stated in claim4, the origination-only portable telephone is disconnected from a powersupply if any input operation is not made in a predetermined time afterthe connection of the origination-only portable telephone to the powersupply or upon the detection of termination of a call.

Thus, the power consumption of the origination-only portable telephonecan be reduced and the origination-only portable telephone can be formedin a small, lightweight construction.

In a portable telephone system according to an invention stated in claim5, an origination-only accounting control means included in theswitching system of the portable telephone system sends datarepresenting the cumulative number of used message units to theorigination-only portable telephone every termination of a call, and acall information display means included in the origination-only portabletelephone displays data representing the cumulative number of usedmessage units.

Thus, the origination-only portable telephone is small and lightweightas compared with a origination-only portable telephone which manages theresidual number of message units, and the security of the portabletelephone system can remarkably be enhanced.

In a portable telephone system according to an invention stated in claim6, the plurality of portable telephones of the portable telephone systeminclude originating-and-receiving portable telephones, the accountingmeans of the switching system counts the numbers of message units usedby the origination-only portable telephones and theoriginating-and-receiving portable telephones identified by terminalidentifying information.

Thus, a high-security portable telephone system including small,lightweight origination-only portable telephones can be constructed byadding only a origination-only accounting control means to the switchingsystem of an ordinary portable telephone system.

In a portable telephone system according to an invention stated in claim7, an accounting means included in a switching system counts the numberof message units used by a prepaid type portable telephone identified byterminal identifying information assigned thereto, a prepaid chargecontrol means denies a call originating operation and a call receivingoperation of the prepaid type portable telephone upon the increase ofthe number of message units used by the prepaid type portable telephoneidentified by the terminal identifying information to a predeterminednumber, and accepts a call originating operation and a call receivingoperation of the prepaid type portable telephone identified by theterminal identifying information upon the reception of the terminalidentifying information and charging information.

Thus the security of the portable telephone system can be remarkablyenhanced.

In a portable telephone system according to an invention stated in claim8, an automatic accounting means reads the terminal identifyinginformation assigned to the prepaid type portable telephone by aterminal identifying information reader, receives money receptioninformation by a money input means, and sends money information togetherwith the read terminal identifying information to a prepaid chargecontrol means upon the reception of predetermined money information.

Thus, the portable telephone system is easy to use.

In a portable telephone system stated in claim 9, the automaticaccounting means encrypts the terminal identifying information and themoney information into corresponding codes by a predetermined encryptingprocedure, and sends the codes to the prepaid charge control means.

Thus, the security of the portable telephone system is improvedremarkably.

In a portable telephone system according to an invention stated in claim10, portable telephones include simple portable telephones each havingan accounting system which counts the cumulative number of used messageunits stored in a data base, converts the cumulative number of usedmessage units at predetermined time intervals into a charge and chargesthe subscriber for the charge. Further, prepaid type simple portabletelephones each having a prepaid charge system which reads the number ofresidual prepaid message units from the data base, subtracts the numberof used message units from the number of residual prepaid message unitsduring a call to allow the prepaid type simple portable telephone tofunction until the message units corresponding to the prepaid amount ofmoney are depleted. A base radio station identifies the portabletelephone which made a call as the simple portable telephone or theprepaid type simple portable telephone, and executes an accountingprocedure according to an accounting method for the portable telephonewhich made a call.

Thus, the prepaid type portable telephone can be formed in a small,lightweight construction, and the security of the portable telephonesystem can be enhanced.

In a portable telephone system according to an invention stated in claim11, a base radio station checks the number of residual message unitsduring a call, sends alarm information to the calling party upon thedecrease of the number of residual message units to predeterminednumber, and disconnects the line forcibly upon the depletion of all theresidual message units.

Thus, the prepaid type portable telephone can be formed in a small,lightweight construction, and the security of the portable telephonesystem can be enhanced.

In a portable telephone system according to an invention stated in claim12, the base radio station allows a fixed number of additional messageunits after the number of residual message units has decreased to zero.

Thus, the prepaid type portable telephone can be formed in a small,lightweight construction, the security of the portable telephone systemcan be enhanced, and the reduction of prepaid type portable telephonerecovery percentage can be prevented.

In a portable telephone system according to an invention stated in claim13, the base radio station sends information about the time of call, acalled party and a residual charge to a base radio station to which thecontrol of the portable telephone is handed over due to the movement ofthe location of the portable telephone.

Thus, the prepaid type portable telephone can be formed in a small,lightweight construction and the security of the portable telephonesystem can be enhanced.

In a portable telephone system according to an invention stated in claim14, the prepaid type simple portable telephone is encased in a simple,folding case formed simply by folding a cardboard.

Thus, the simple portable telephone system can be formed in a small,lightweight construction and the security of the portable telephonesystem can be enhanced.

In a portable telephone system according to an invention stated in claim15, the simple, folding case has a flip section to prevent an erroneousoperation.

Thus, the simple portable telephone system can be formed in a small,lightweight construction and the portable telephone system prevents anerroneous operation.

In a portable telephone system according to an invention stated in claim16, the flip section has a folded advertising portion.

Thus, the simple portable telephone system can be formed in a small,lightweight construction and the added value of the portable telephonesystem is increased.

In a portable telephone system according to an invention stated in claim17, the simple, folding case has a covering portion for protecting theprepaid type simple portable telephone. The prepaid type simple portabletelephone is contained in the covering portion. The prepaid type simpleportable telephone is slid relative to the covering portion for anoperation to make a call.

Thus, the simple portable telephone system can be formed in a small,lightweight construction and the portable telephone system prevents anerroneous operation.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of a portable telephone system in a firstembodiment according to the present invention;

FIG. 2 is a plan view of a origination-only portable telephone employedin the portable telephone system of FIG. 1;

FIG. 3 is a flow chart of a procedure for operating the origination-onlyportable telephone employed in the portable telephone system of FIG. 1;

FIG. 4 are time charts of assistance in explaining operations fororiginating a call by the portable telephone in the portable telephonesystem of FIG. 1;

FIG. 5 is a schematic perspective view of a residual message unitdisplay included in the origination-only portable telephone of FIG. 2;

FIG. 6 is a plan view of a origination-only portable telephone in asecond embodiment according to the present invention employed in theportable telephone system of FIG. 1;

FIG. 7 is a block diagram of a portable telephone system in a thirdembodiment according to the present invention;

FIG. 8 is a schematic perspective view of an automatic accounting deviceincluded in the portable telephone system of FIG. 7;

FIG. 9 is diagrammatic view of a portable telephone system in a fourthembodiment according to the present invention;

FIG. 10 is a block diagram of a base radio station included in theportable telephone system in the fourth embodiment according to thepresent invention;

FIG. 11 is a time chart of assistance in explaining a calling procedurefor calling a called party to be carried out by the portable telephonesystem in the fourth embodiment according to the present invention;

FIG. 12 are a development and a perspective view, respectively, of afolding simple case formed by folding a cardboard, employed in theportable telephone system in the fifth embodiment according to thepresent invention;

FIG. 13 are a development and a perspective view, respectively, ofanother folding simple case formed by folding a cardboard, employed inthe portable telephone system in the fifth embodiment according to thepresent invention;

FIG. 14 are a development and a perspective view, respectively, of athird folding simple case employed in the portable telephone system inthe fifth embodiment according to the present invention;

FIG. 15 are a development, a perspective view and a perspective view,respectively, of a fourth folding simple case formed by folding acardboard, employed in the portable telephone system in the fifthembodiment according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in detail in terms of thedescription of a best mode for carrying out the present invention withreference to the accompanying drawings.

First Embodiment

Referring to FIG. 1 showing a portable telephone system in a firstembodiment according to the present invention, portable telephones 1 (1Aand 1B) move around in a radio coverage area covered by a base radiostation 2 connected to a switching system 3. The portable telephones 1include originating-and-receiving portable telephones 1A having ordinarytelephone functions capable of originating a call and of receiving acall, and origination-only portable telephone 1B capable of onlyoriginating a call. The switching system 3 includes a line connectioncontrol unit 8, as a call connecting function, for controlling anoperation to connect a line of the base radio station 2 and a publicnetwork 9; an accounting unit 4, as an ordinary accounting function, tocharge a call made by the portable telephone 1 identified by a terminalidentification number assigned thereto according to the location of thecalled party; and an accounting data storage unit 5 which stores acharge determined by accounting at the completion of a call. A publicnetwork 9, connected to the switching system 3 accepts an originatingrequest from the switching system 3, and calls an optional subscriberconnected to the public network 9.

In the first embodiment, the switching system 3 has, in addition to theordinary accounting function, an origination-only accounting controlunit 6, as a origination-only portable telephone managing function, tomonitor the number of message units used by the origination-onlyportable telephone 1B identified by the terminal identification numberand to deny the origination of a call by the origination-only portabletelephone 1B upon the increase of the number of message units to apredetermined number. The origination-only accounting control unit 6accepts the origination of a call made by the origination-only portabletelephone 1B when a prescribed input for the origination-only portabletelephone 1B is given thereto by a system operator by operating apredetermined terminal device 7, or the like. The prescribed input maybe used after the last origination of a call with sufficient messageunits by the origination-only portable telephone 1B has been made. Thus,the origination-only portable telephone 1B can be controlled by theswitching system 3 of an ordinary portable telephone system when thefunctions of the switching system 3 are modified. The security of theportable telephone system is improved remarkably because theorigination-only portable telephone 1B need not manage the number ofmessage units where the switching system 3 does so.

As shown in FIG. 2, the origination-only portable telephone 1B employedin the portable telephone system in the first embodiment has a case 10of a size that enables the case 10 to be held by one hand, having acontrol panel provided with a power key 11, a talk key 12, a terminationkey 13, operating keys 14 including numeric keys for numerals 0 to 9,function keys for sharp (#) and programming (P), a microphone 15, aspeaker 16, a residual message unit indicator 17, and a power/callpermission indicator 18. The origination-only portable telephone 1B isprovided with an antenna 19. A battery is contained in the case 10 sothat the battery cannot be changed by the user. The origination-onlyportable telephone 1B, as compared with the originating-and-receivingportable telephone 1A, is simple in configuration; that is, a liquidcrystal display, a call signal generator, a memory unit for storingtelephone numbers and such, a sound volume controller, a clock, an alarmand a connector are omitted from the origination-only portable telephone1B. Therefore, the origination-only portable telephone 1B has arelatively small number of parts, and is small, lightweight andinexpensive.

Referring to FIG. 3, when the power key 11 is operated to connect theorigination-only portable telephone 1B to the power supply in step SP1,the power/call permission indicator 18 lights up, for example, in red instep SP2. Then, the origination-only portable telephone 1B is operatedto carry out a prescribed originating procedure including, for example,a position registering operation to inform the base radio station 2 ofthe position of the origination-only portable telephone 1B in step SP3.Then, the power/call permission indicator 18 lights up in green in stepSP4. Then, the user operates the talk key 12 in step SP5, operates thenumeric keys 14 to enter the telephone number of the called party instep SP6, and starts taking in step SP7 after the origination-onlyportable telephone 1B has been connected to the called party. Step SP6in which the numeric keys 14 is operated to enter the telephone numbermay be executed before step SP5 in which the talk key 12 is operated.

When talking in step SP7 has ended or if it is decided in step SP8 thatthe telephone number entered in step SP6 is wrong, the termination key13 is operated in step SP9 to disconnect the origination-only portabletelephone 1B from the power supply. Consequently, the power/callpermission indicator 18 is turned off in step SP10. If the called partyterminates talking in step SP11 during talk in step SP7, theorigination-only portable telephone 1B is disconnected automaticallyfrom the power supply, and the power/talk permission indicator 18 isturned off accordingly in step SP10. If it is decided in step SP12 thatany input operation is not executed for a predetermined time after theexecution of step SP5 or SP6, the origination-only portable telephone 1Bis disconnected automatically from the power supply and the power/talkpermission indicator 18 is turned off in step SP10. Since theorigination-only portable telephone 1B does not need any standby modeand is connected to the power supply only when the origination-onlyportable telephone 1B is used for talking, the consumption of thebattery is reduced to secure the life of the battery as necessary for apredetermined number of message units.

The battery can be changed and the origination-only portable telephone1B recycled only by the operator of the portable telephone system or anauthorized person. Therefore, the case 10 of the origination-onlyportable telephone 1B is a sealed case, and is internally provided withan unsealing preventing mechanism which, for example, makes thereclamation of the internal circuit of the origination-only portabletelephone 1B impossible if the case 10 is unsealed without entering apassword. Thus, the dishonest change of the terminal identificationnumber can be prevented.

FIG. 4(A) shows operations for calling the called party through the baseradio station 2, the switching system 3 and the public network 9 whenthe portable telephone 1 starts an operation for talking in step SP7.Referring to FIG. 4(A), when the calling party operates the portabletelephone 1 to enter the telephone number of the called party, theportable telephone 1 transmits an identification number assigned to thecalling party together with the telephone number through the base radiostation 2 to the switching system 3 (ST1). The switching system 3retrieves and examines accounting information about the identificationnumber of the calling party to see if there is residual message units.If there is residual message units, the switching system 3 calls thecalled party through the public network 9. (ST2).

When the called party responds to the call, the switching system 3 sendsa signal to that effect to the portable telephone 1 (ST3), connects thelines, sets the lines in a busy state, and starts counting the number ofmessage units (ST4). If the calling party terminates the call duringcommunication, the portable telephone 1 informs the switching system 3through the base radio station 2 of the termination of the call (ST5).Then, the switching system 3 instructs the called party through thepublic network 9 to disconnect the line, stop counting the number ofmessage units (ST6), and inform the portable telephone 1 of the numberof residual message units (ST7). As shown in FIG. 4(B), when theportable telephone 1 is operated for originating a call (ST1), theswitching system 3 examines the accounting information identified by theidentification number and denies the call originating operation of thecalling party if the number of message units is zero (ST8).

Thus, the portable telephone system makes the switching system 3transfer data representing the number of residual message units throughthe base radio station 2 upon the termination of the call. The number ofresidual message units is indicated by the residual message unitindicator 17 on the origination-only portable telephone 1B. As shown inFIG. 5, the residual message unit indicator 17 is formed by disposingthree small heating elements 20A, 20B and 20C at positions respectivelycorresponding to openings 21A, 21B and 21C formed between numerals 80and 50, between numerals 50 and 30, between numerals 30 and 5 indicatingthe numbers of residual message units, and covering the small heatingelements 20A, 20B and 20C with a thermosensible sheet 22. A current issupplied to the small heating element corresponding to the number ofresidual message units represented by the data on the number of residualmessage units, for example, the heating element 20A, to heat a portion22A of the thermosensible sheet 22 corresponding to the heating element20A. Consequently, the portion 22A turns black. Since the portion 22Aremains black, power is not wasted and the life of the battery isextended accordingly.

The origination-only portable telephone 1B capable of making only callsof a contract number of message units, such as 100 message units, isavailable from a station stall or a convenience store. Since theorigination-only portable telephone 1B is capable only of originating acall, any contract procedures necessary for using ordinary portabletelephones are not necessary at all for using the origination-onlyportable telephone 1B. The user needs only to buy the origination-onlyportable telephone 1B and use it. After originating calls for thepredetermined number of message units, the origination-only portabletelephone 1B is returned to the store where the origination-onlyportable telephone 1B was procured or to the operator of the system. Theoperator of the system unseals the origination-only portable telephone1B by a predetermined procedure, replaces the battery with a new one,and operates the terminal device 7 to enter data instructing theswitching system 3 to accept the call of a predetermined number ofmessage units made by the origination-only portable telephone 1Bidentified by the terminal identification number.

When the portable telephone makes a call, the switching system countsthe number of message units used by the portable telephone identified bythe terminal identification number. The switching system denies the callorigination of the origination-only portable telephone identified by theterminal identification number after the predetermined number of messageunits have been used. If a predetermined input is given to the switchingsystem, the switching system accepts the call origination of theorigination-only portable telephone. Thus, the origination-only portabletelephone can be formed in a small, lightweight construction, and thesecurity of the portable telephone system is improved remarkably.

Although only the system operator or an authorized person are allowed tochange the battery in the foregoing first embodiment, the battery may bechanged by the user. If the user is allowed to change the battery, thebattery is changed by the user if the origination-only portabletelephone is left unused for a long time and the battery has exhausteddue to natural discharge, and the origination-only portable telephonecan be used until all the contract message units are used.

Second Embodiment

An origination-only portable telephone 1B in a second embodimentaccording to the present invention to be used in the portable telephonesystem of the present invention is shown in FIG. 6, in which parts likeor corresponding to those shown in FIG. 2 are designated by the samereference characters. The origination-only portable telephone 1B shownin FIG. 6 is not provided with any key corresponding to the power key 11of the origination-only portable telephone 1B shown in FIG. 2.Therefore, the origination-only portable telephone 1B in the secondembodiment has a simple control panel, needs a reduced number of parts,and is small, lightweight and inexpensive. Practically, theorigination-only portable telephone 1B of FIG. 6 is connected to a powersupply by depressing one of the numeric keys 14 thereof, and is operatedby the operating procedure comprising the steps previously describedwith reference to FIG. 3 for a telephone call.

Third Embodiment

A portable telephone system in a third embodiment according to thepresent invention is shown in FIG. 7, in which parts like orcorresponding to those previously described with reference to FIG. 1 aredesignated by the same reference characters. The portable telephonesystem shown in FIG. 7 employs, instead of the origination-only portabletelephones 1B shown in FIG. 1, ordinary originating-and-receivingportable telephones 1A having an accounting function and prepaid typeportable telephones 30 which can make calls of a predetermined number ofmessage units corresponding to a prepaid amount of money. Theoriginating-and-receiving portable telephones 1A and the prepaid typeportable telephones 30 move around in a radio coverage area covered by abase radio station 2. A switching system 3 is provided with a prepaidcharge control unit 31 instead of the origination-only accountingcontrol unit 6 of FIG. 1.

The prepaid charge control unit 31 monitors the number of message unitsused by the prepaid type portable telephone 30 identified by a terminalidentification number with reference to the contents of an accountingdata storage unit 5, The prepaid charge control unit 31 denies the callorigination of the prepaid type portable telephone 30 identified by theterminal identification number. When a call for the prepaid typeportable telephone 30 occurs, gives a call-not-accepted signal to thecalling party if the predetermined number of message units allowed tothe prepaid type portable telephone 30 have been used. An automaticaccounting device 32 is connected to the prepaid charge control unit 31.The contents of a storage location in the accounting data storage unit 5corresponding to data representing the terminal identification numberand a charge and provided by the automatic accounting device 32 areupdated, and a number of message units is set according to a charge forthe terminal identification number. Consequently, the prepaid typeportable telephone 30 identified by an updated terminal identificationnumber can be used for call originating and call receiving operations.

Referring to FIG. 8, the automatic accounting device 32 is provided inits upper end wall with an opening 33 for receiving the prepaid typeportable telephone 30. A connector which mates with a connector, notshown, disposed on the bottom wall of the prepaid type portabletelephone 30 is disposed in the opening 33. When the prepaid typeportable telephone 30 is inserted in the opening 33, the terminalidentification number stored in the ROM of the prepaid type portabletelephone 30 is read automatically. The automatic accounting device 32is provided on its front panel with a coin slot 34, a card slot 35, aliquid crystal display 36, a keyboard 37 and a change return pocket 38.When a predetermined amount of money is deposited through the coin slot34 into the automatic accounting device 32, the automatic accountingdevice 32 sends data representing the amount of the prepaid money andthe terminal identification number to the prepaid charge control unit31. If the prepaid type portable telephone 30 is inserted in the opening33 and a credit card is inserted in the card slot 35, a messagerequesting an operation of a keyboard to enter a password number isdisplayed on the liquid crystal display 36. When the password number isentered, the automatic accounting device 32 sends the card number andthe password number to, for example, a card management center, notshown, to request acceptance. When the card management center gives anacceptance, the automatic accounting device 32 sends data representing apredetermined amount of money as prepaid charge and the terminalidentification number to the prepaid charge control unit 31.

In the third embodiment, the switching system counts the number ofmessage units used by the prepaid type portable telephone when theprepaid type portable telephone identified by the terminalidentification number makes a call, denies call origination and callreception by the prepaid type portable telephone after the predeterminednumber of message units have been used and, if a predetermined input isgiven by the automatic accounting device, accepts the call originationand the call reception of the prepaid type portable telephone. Thus, thesecurity of the portable telephone system is improved remarkably.

Although the portable telephone system in the third embodiment sends theterminal identification number and the prepaid amount of money simply tothe prepaid charge control unit 31, the security of the portabletelephone system will further be improved if the prepaid amount of moneyand the terminal identification number are encrypted into correspondingcodes by a predetermined encrypting procedure and the codes are sent tothe prepaid charge control unit 31. In the second embodiment, a prepaidamount of money is paid by either depositing cash in the automaticaccounting device 32 or inserting a credit card in the automaticaccounting device 32. However, the automatic accounting device 32 may bedesigned to accept payment by only cash or only a credit card or theautomatic accounting device 32 may be designed to accept payment by aprepaid card. Although the foregoing portable telephone system requirespayment of a predetermined amount of money in cash or by a credit card,the portable telephone system may be designed to accept payment of anyamount of money determined by the user. The accessibility of theautomatic accounting device 32 will be further improved if a prepayingprocedure is carried out on an interactive basis by using informationdisplayed on the liquid crystal display 36.

In the third embodiment, a connector is disposed in the opening 33 ofthe automatic accounting device 32, the respective internal circuits ofthe prepaid type portable telephone 30 and the automatic accountingdevice 32 are connected electrically when the prepaid type portabletelephone 30 is inserted in the opening 33, and the automatic accountingdevice 32 executes the automatic accounting procedure. However, theautomatic accounting device 32 may be provided with a magneticallyshielded recessed pocket, and the automatic accounting procedure may becarried out by putting the prepaid type portable telephone 30 into themagnetically shielded pocket, closing the magnetically shielded pocketwith a shielding cover and connecting the respective internal circuitsof the prepaid type portable telephone 30 and the automatic accountingdevice 32 by radio. Such an automatic accounting procedure reducesmechanical connections, improves the accessibility of the automaticaccounting device 32, and improves the durability and the confidence ofthe automatic accounting device 32.

Fourth Embodiment

FIG. 9 is diagrammatic view of a portable telephone system in a fourthembodiment according to the present invention and FIG. 10 is a blockdiagram of a base radio station included in the portable telephonesystem of FIG. 9 in the fourth embodiment accoring to the presentinvention. Practically, the portable telephone system in the fourthembodiment is supposed to be a PHS (personal handyphone system).Referring to FIGS. 9 and 10, simple portable telephones 41 move aroundin a radio coverage area covered by a base radio station 51. Theportable telephone system includes an accounting system and a prepaidcharge system. The accounting system counts the number of used messageunits (accounting information) stored in a data base 71 kept in amaintenance center 70, converts the number of used message units used ina predetermined period into a corresponding amount of money and billsthe user for a charge. Prepaid type simple portable telephones 42 movearound in the radio coverage area covered by the base radio station 51.The prepaid charge system subtracts the number of used message units forthe distance between the prepaid type portable telephone 42 and thecalled party from the number of residual message units (residual chargeinformation). The prepaid charge system allows the use of the prepaidtype simple portable telephone 42 until all the message unitscorresponding to the amount of the prepaid money are used. Whereas theuse of the simple portable telephone 41 needs to make a contract with arelevant common carrier, the prepaid type simple portable telephone 42does not need to make any contract with any common carrier. The prepaidtype simple portable telephone 42 can be procured from a station stall,a portable telephone bending machine.

A base radio station 51 discriminates between the simple portabletelephone 41 and the prepaid type simple portable telephone 42 andcarries out a prescribed accounting procedure for the portable telephonewhich originated a call, i.e., the simple portable telephone 41 or theprepaid type simple portable telephone 42. A line connection controlunit 61 connects the lines of the base radio station 51 to a publicnetwork. Terminal authentication information authenticating the simpleportable telephones 41 and the prepaid type simple portable telephones42, accounting information (accounting information for the simpleportable telephones 41 and residual charge information for the prepaidtype simple portable telephones 42), position information, securityinformation and such are stored in the data base 71 kept in themaintenance center 70.

A transmitter 52 and a receiver 53 serve as radio interfaces between theportable telephones and the base radio station 51. A time divisioncontrol unit 54 carries out what is called a TDMA/TDD procedure (timedivision multiple access/time division duplex procedure) to allocatecommunication channels to time slots included in radio channels, and toassemble and disassemble radio frames for a control channel andcommunication channel. A coding/decoding unit 55 carries out an ADPCMprocedure (adaptive differential PCM procedure) to convert ADPCM signalsof 32 kbit/s used in a radio section for the simple portable telephones41 and the prepaid type simple portable telephones 42 and μ-low PCMsignals of 64 kbit/s used by an NTT digital network.

A control unit 56 includes a CPU and a storage device, and communicateswith the maintenance center 70 through special lines to carry outoperations for position registration, authentication, call connectionand account control. In the fourth embodiment, control unit 56determines whether the portable telephone which originated a call is thesimple portable telephone 41 or the prepaid type simple portabletelephone 42, and controls an accounting system for the portabletelephone which originated a call. If the portable telephone whichoriginated a call is identified as the simple portable telephone 41, thecontrol unit 56 manages only service time and the called party and givesinformation about service time and the called party to the maintenancecenter 70 upon the termination of the call. If the portable telephonewhich originated a call is identified as the prepaid type of simpleportable telephone 42, the control unit 56 controls, in addition toservice time and the called party, information about the residual chargefor the prepaid type of simple portable telephone 42. Thus, the controlunit retrieves the above information from the data base 71 of themaintenance center 70, according to the service time and the calledparty.

The operation of the portable telephone system in the fourth embodimentaccording to the present invention will be described hereinafter.

FIG. 11 is a time chart of assistance in explaining a called partycalling procedure to be carried out by the portable telephone system inthe fourth embodiment according to the present invention. A called partycalling procedure to be carried out when the simple portable telephone41 originates a call is a known procedure and hence the descriptionthereof will be omitted.

When the telephone number of a called party is entered by operating theprepaid type simple portable telephone 42, the prepaid type simpleportable telephone 42 sends the telephone number of the called party andthe ID number of the calling party to the base radio station 51 in stepST1. Upon the reception of the telephone number of the called party andthe ID number of the calling party, the base radio station 51 examinesthe ID number of the calling party in step ST2 to determine whether ornot the portable telephone originated a call is the prepaid type simpleportable telephone 42 having a prepaid charge system.

If the portable telephone which originated a call is identified as theprepaid type simple portable telephone 42, the base radio station 51sends a user's residual charge information request signal to the database 71 in step ST3, and examines the user's residual charge informationbased on a user's residual charge response signal from the data base 71in step ST4 to see if there are any residual message units in step ST5.If there are some residual message units, the base radio station 51calls the called party through the line connection control unit 61 ofthe public network in step ST6. When the called party answers the call,the line connection control unit 61 of the public network informs thecalling party that the called party has answered through the base radiostation 51 in step ST7. Then, the base radio station 51 starts countingthe residual message units of the calling party during conversation instep ST8 and connect the line through the line connection control unit61 of the public network in step ST9.

The base radio station 51 checks the residual message units of thecalling party during conversation in step ST10, gives a residual messageunit depletion alarm, such as a background music. The residual messageunit indicates a predetermined number of residual message units to thecalling party in step ST11. The base radio station 51 disconnects theline upon the depletion of the residual message units. If the prepaidsimple portable telephone 42 has only a few residual message units, itis possible that the line is disconnected before conversations arecompleted. Therefore, the prepaid simple portable telephone 42 will notbe used until all the residual message units are depleted and hence thereduction of prepaid type portable telephone recovery percentage can beprevented.

The connection may be extended for a period within a fixed servicemessage units, such as service message units equivalent to one minuteduring which a background music or the like is inserted, when theresidual message units have been depleted during conversation. Inaddition further origination of a call may be denied even if there areresidual service message unit after the completion of conversations.

If the call is terminated before the residual message units are depletedin step ST12, the base radio station 51 disconnects the communicationlines in step ST13, ends an operation to count the residual message unitof the calling party in step ST14, informs the calling party and thedata base 71 of the number of residual message units in step ST15. Theinformation of the calling party of the number of residual message unitsis not necessarily necessary. If the prepaid simple portable telephone42 moves during the call, the base radio station 51 managing thecommunication control changes and hence service time, information aboutthe called party and information about the residual message units aretransmitted to the base radio station 51 to which the management hasbeen handed over.

The number of residual message units can be changed to a number ofresidual message units equivalent to a prepaid amount of money paid forthe prepaid type simple portable telephone 42 by operating the automaticaccounting device 32 shown in FIG. 8. When the number of residualmessage units is thus rewritten, the number of residual message unitsstored in the data base 71 is rewritten accordingly by radio through theline connection control unit 61 of the public network. At the same time,a complicated accounting procedure which is currently carried out on thebasis of service time, the distance between the calling party and thecalled party and contract service by the simple portable telephone 41can be achieved by, for example, a simple accounting procedure requiringonly several steps of weighting by the addition of such a service.

Fifth Embodiment

A simple folding case formed by folding a cardboard, employed in aportable telephone system in a fifth embodiment according to the presentinvention is shown in FIGS. 12(a) and 12(b), in which parts like orcorresponding to those of the fourth embodiment are designated by thesame reference characters and the description thereof will be omitted.FIG. 12(a) is a development of the simple folding case, and FIG. 12(b)is a perspective view of the simple folding case containing a prepaidtype simple portable telephone 42. In FIG. 12(a), long and short dashlines are inside folding lines. The case has an upper front section 81provided with a slit 81 a, a speaker grille 81 b and an opening 81 cthrough which a LED of the prepaid type simple portable telephone 42 isexposed, and covering an upper portion of the front surface of theprepaid type simple portable telephone 42, a top section 82 providedwith an opening 82 a through which the antenna of the prepaid typesimple portable telephone 42 is projected, and covering the upper endsurface of the prepaid type simple portable telephone 42, a back section83 covering the back surface of the prepaid type simple portabletelephone 42, a bottom section 84 for covering the bottom surface of theprepaid type simple portable telephone 42, and a flip section 85provided with a tuck 85 a and covering a lower portion of the frontsurface of the prepaid type simple portable telephone 42. The tuck 85 ais inserted in the slit 81 a to cover the front surface of the prepaidtype simple portable telephone 42 with the flip section 85 to preventthe erroneous operation of the prepaid type simple portable telephone42.

Another simple folding case employed in the portable telephone system inthe fifth embodiment according to the present invention is shown inFIGS. 13(a) and 13(b). FIG. 13(a) is a development of the simple foldingcase, and FIG. 13(b) is a perspective view of the simple folding casecontaining a prepaid type simple portable telephone 42. In FIG. 13(a),alternate long and short dash lines are inside folding lines, and brokenlines are outside folding lines. The folding case has bottom sections91-1 and 91-2 forming a double bottom wall and covering the bottomsurface and portions of the side surfaces of the prepaid type simpleportable telephone 42, flip sections 92-1 and 92-2 forming a double flipand covering the front surface of the prepaid type simple portabletelephone 42 to prevent the erroneous operation of the prepaid typesimple portable telephone 42, a snap stud 92 a formed on the flipsection 92-2, a front section 93 provided with a microphone grille 93 a,and opening 93 b in which the operating keys of the prepaid type simpleportable telephone 42 are arranged and a snap socket 93 c in which thesnap stud 92 a fits, and covering the front surface and the sidesurfaces of the prepaid type simple portable telephone 42, an topsection 94 provided with an opening through which the antenna of theprepaid type simple portable telephone 42 projects, and covering theupper surface of the prepaid type simple portable telephone 42, and aback section 95 covering the back surface and the side surfaces of theprepaid type simple portable telephone 42. When encasing the prepaidtype simple portable telephone 42 in the case, the prepaid type simpleportable telephone 42 is placed on the back section 95 of the unfoldedcase, and then the sections are folded along the folding lines.

A third simple folding case employed in the portable telephone system inthe fifth embodiment according to the present invention is shown inFIGS. 14(a) and 14(b). FIG. 14(a) is a development of the simple foldingcase, and FIG. 14(b) is a perspective view of the simple folding casecontaining a prepaid type simple portable telephone 42. In FIG. 14(a),alternate long and short dash lines are inside folding lines, and brokenlines are outside folding lines. This folding case is formed by addingan advertising section 96 to one side edge of the flip 92-2 of FIG. 13.Advertisements, such as those of shops, are printed on the inner surfaceof the advertising section 96. Therefore, a prepaid type simple portabletelephone 42 encased in this folding case is suitable for use as apresent.

A fourth simple folding case employed in the portable telephone systemin the fifth embodiment according to the present invention is shown inFIGS. 15(a), 15(b) and 15(c). FIG. 15(a) is a development of the simplefolding case, FIG. 15(b) is a perspective view of the simple foldingcase containing a prepaid type simple portable telephone 42 and FIG.15(c) is a perspective view of the simple folding case and the prepaidtype simple portable telephone 42 half pulled out of the simple foldingcase for use. In FIG. 15(a), alternate long and short dash lines areinside folding lines, and broken lines are outside folding lines. Acovering portion 100 protects the prepaid type simple portable telephone42, and a sliding portion 110 serves as a cover to prevent the erroneousoperation of the prepaid type simple portable telephone 42 while theprepaid type simple portable telephone 42 is not used and is pulled offwhen the prepaid type simple portable telephone 42 is used. An upperfront section 101 covers an upper portion of the front surface of theprepaid type simple portable telephone 42, an upper section 102 isprovided with an opening 102 a through which an antenna is projected andcovers the top surface of the prepaid type simple portable telephone 42,side sections 103 for covering the side surfaces of the prepaid typesimple portable telephone 42, a back section 104 covering the backsurface of the prepaid type simple portable telephone 42, a lower frontsection 105 is provided with microphone grille 105 a and covers thelower portion of the front surface of the prepaid type simple portabletelephone 42, and an elastic connector 106 having one end attached to alower portion of the back section 104 and the other end attached to alower portion of the back section 104 of the sliding portion 110. Abottom section 107 covers the bottom surface of the prepaid type simpleportable telephone 42.

INDUSTRIAL APPLICABILITY

As is apparent from the foregoing description, the portable telephonesystem in accordance with the present invention is suitable for use as aportable telephone system using portable telephones moving in a radiocoverage area covered by a base radio station connected to a switchingsystem and including origination-only portable telephones capable ofonly originating a call through the base radio station.

The portable telephone system in accordance with the present inventionis suitable for use as a portable telephone system including a baseradio station connected through a line connection control unit to apublic network, portable telephones moving in a radio coverage areacovered by the base radio station and capable of achieving communicationthrough the base radio station, and a data base connected to the baseradio station and managing data about the portable telephones.

What is claimed is:
 1. A wireless telephone system including: aswitching system, a base radio station connected to the switchingsystem, and portable telephones in a radio coverage area covered by thebase radio station and including origination-only portable telephonescapable of only originating a call through the base radio station; saidswitching system comprising: an accounting means for counting the numberof message units used by each of the origination-only portabletelephones each identified by terminal identifying information; and anorigination-only accounting control means supporting a first accessmode, a second access mode, and a third access mode, the first accessmode denying the originating operation of the origination-only portabletelephone when the number of message units used by the origination-onlyportable telephone identified by the terminal identifying informationreaches a predetermined number of message units, the second access modepermitting the originating operation of the origination-only portabletelephone identified by the terminal identifying information when apredetermined input operation is executed, and the third access modeproviding an automatic extension of the communication for continuing theoperation of the origination-only portable telephone, which startsbefore the number of message units of the origination-only portabletelephone reaches zero.
 2. The wireless telephone system according toclaim 1, wherein the origination-only portable telephone includes apower switch that changes its state from off to on each time theorigination-only portable telephone is used for originating a call toreduce power consumption during a wait state of the portable telephone.3. The wireless telephone system according to claim 1, wherein theorigination-only portable telephone has a control panel and numeric keysfor entering telephone number information for a call arranged on thecontrol panel, the numeric keys facilitating connection of theorigination-only portable telephone to a power supply.
 4. The wirelesstelephone system according to claim 2, wherein the origination-onlyportable telephone is provided with a power supply cut-off means whichdisconnects the origination-only portable telephone from the powersupply when any input operation is not made in a predetermined timeafter the connection of the origination-only portable telephone to thepower supply, or when termination of a call is detected.
 5. The wirelesstelephone system according to claim 1, wherein the origination-onlyaccounting control means included in the switching system sends datarepresenting the cumulative number of message units to theorigination-only portable telephone every termination of a call, andeach origination-only portable telephone is provided on its controlpanel with a call information display means for displaying datarepresenting the cumulative number of used message units everytermination of said call.
 6. The wireless telephone system according toclaim 1, wherein the plurality of portable telephones include, inaddition to those origination-only portable telephones,originating-and-receiving portable telephones, the accounting means ofthe switching system counts the numbers of message units used by theorigination-only portable telephones and the originating-and-receivingportable telephones identified by terminal identifying information.
 7. Aportable telephone system including: a switching system, a base radiostation connected to the switching system and portable telephone in aradio coverage area covered by the base radio station; said portabletelephones including prepaid type portable telephones being allowed tooriginate calls until a predetermined number of message units aredepleted, and said switching system comprising: an accounting means forcounting the number of message units used by each of the prepaid typeportable telephones each identified by terminal identifying informationin addition to that of message units used by each of the ordinaryportable telephones, and a prepaid charge control means supporting afirst access mode, a second access mode, and a third access mode, thefirst access mode denying an originating operation and a receivingoperation of each prepaid type portable telephone identified by theterminal identifying information when the number of message units usedby the prepaid type portable telephone identified by the terminalidentifying information reaches a predetermined number of message units,the second access mode permitting the originating operation and thereceiving operation of the prepaid type portable telephone identified bythe terminal identifying information upon the reception of the terminalidentifying information identifying the prepaid type portable telephone,and accounting information, the third access mode providing an automaticextension of the communication for continuing the operation of theorigination-only portable telephone, which starts before the number ofmessage units of the origination-only portable telephone reaches zero.8. The portable telephone system according to claim 7, furthercomprising an automatic accounting means including a terminalidentifying information read means for reading terminal identifyinginformation assigned to each of the prepaid type portable telephones,and money information input means for accepting money information, andcapable of sending the accepted money information together with the readterminal identifying information to the prepaid charge control means. 9.The portable telephone system according to claim 8, wherein theautomatic accounting means encrypts the terminal identifying informationand the money information into corresponding codes by a predeterminedencrypting procedure, and sends the codes to the prepaid charge controlmeans.
 10. A portable telephone system including: a base radio stationconnected through a line connection control unit to a public network;portable telephones moving in a radio coverage area covered by the baseradio station and achieving communication through the base radiostation; and a data base connected to the base radio station andmanaging data on each of the portable telephones; said portabletelephones include simple portable telephones each being associated witha charging system for counting the cumulative number of used messageunits for storage in the data base, the charging system converting thecumulative number of used message units at predetermined time intervalsinto a charge and charging the subscriber for the charge, and prepaidtype simple portable telephones each being associated with a prepaidcharge system for reading the number of residual prepaid message unitsfrom the data base, the prepaid charging system subtracting the numberof used message units from the number of residual prepaid message unitsduring a call, and said prepaid type simple portable telephones havingaccess to prepaid communication service until all the prepaid messageunits corresponding to the prepaid amount of money are depleted, andsaid base radio station being capable of identifying the portabletelephone which made a call as the simple portable telephone or theprepaid type simple portable telephone, and of executing a chargingprocedure according to a charging method for the portable telephonewhich made a call, at least one of the simple portable and the prepaidsimple portable having a tamper-resistant housing for disablingcircuitry inside the housing upon opening of the housing without entryof a correct password.
 11. The portable telephone system according toclaim 10, wherein the base radio station checks the number of residualmessage units during a call, sends alarm information to the callingparty when the number of residual message units reaches a predeterminednumber, and disconnects the line forcibly upon the depletion of all theresidual message units.
 12. The portable telephone system according toclaim 10, wherein the base radio station allows a fixed number ofadditional message units after depletion of the number of residualmessage units.
 13. The portable telephone system according to claim 10,wherein the base radio station sends information about the time of call,a called party and a residual charge to a base radio station to whichthe control of the portable telephone is handed over due to the movementof the location of the portable telephone from the radio coverage areacovered by the former base radio station to that covered by the latterbase radio station.
 14. The portable telephone system according to claim10, wherein the prepaid type simple portable telephone is encased in asimple, folding case formed simply by folding a cardboard.
 15. Theportable telephone system according to claim 10, wherein the simple,folding case has a flip to prevent an erroneous operation.
 16. Theportable telephone system according to claim 15, wherein the flip has afolded advertising portion.
 17. The portable telephone system accordingto claim 15, wherein the simple, folding case has a covering portion forprotecting the prepaid type simple portable telephone, the prepaid typesimple portable telephone is contained in the covering portion, and theprepaid type simple portable telephone is slid relative to the coveringportion for an operation to make a call.
 18. A wireless communicationssystem comprising: a switching system, associated with a base station,the base station providing communications service to mobile stations ina radio coverage area, said switching system including a counter forcounting the number of message units used by each of the mobilestations; and an accounting controller for supporting a first accessmode, a second access mode, and a third access mode of thecommunications service to a particular one of the mobile stations, thefirst access mode denying an originating operation of the particularmobile station when the number of message units used by the particularmobile station meets or exceeds a predetermined threshold number ofmessage units, the second access mode permitting the originatingoperation of the particular mobile station when the accountingcontroller accepts a predetermined input operation, the third accessmode providing an automatic extension of the communication forcontinuing the operation of the origination-only portable telephone,which starts before the number of message units of the origination-onlyportable telephone reaches zero.
 19. The communications system accordingto claim 18 wherein the particular mobile station is adapted tooriginate an outgoing call by communicating to the base station andwherein the particular mobile station is arranged to automaticallyswitch power off to its circuitry when not originating or executing theoutgoing call.
 20. The communications system according to claim 18wherein the particular mobile station further comprises a keypad andwherein the input operation comprises a code entered into the keypad.21. The wireless telephone system according to claim 18, wherein theparticular mobile station includes a keypad, a power supply and a powersupply cut-off device for disconnecting the particular mobile stationfrom the power supply unless a certain code is entered into the keypad.22. The wireless telephone system according to claim 18, wherein theaccounting controller sends data representing the cumulative number ofmessage units to the mobile station after each termination of a call fordisplay on the mobile station.
 23. The wireless communications systemaccording to claim 18, wherein the mobile stations includeorigination-only portable telephones and originating-and-receivingportable telephones, the counter adapted to count the numbers of messageunits used by the origination-only portable telephones, while ignoringthe originating-and-receiving portable telephones identified by mobileidentifiers.
 24. The wireless communications system according to claim18 further comprising a terminal device coupled to the accountingcontroller, the terminal device supporting entry of the input operationand transmitting the input operation to the accounting controller in anencrypted format.
 25. The communications system according to claim 18wherein the particular one of the mobile stations has a tamper-resistanthousing for disabling circuitry of the particular one upon opening ofthe housing without entry of a correct password.